The present invention relates to an airbelt for protecting an occupant of a high-speed moving object, such as a vehicle, in a collision and to an airbelt apparatus, and more specifically, it relates to an airbelt and an airbelt apparatus in which an internal bag is inflated by gas from a gas generator.
An airbelt apparatus is disclosed in Japanese Unexamined Patent Publication (KOKAI) No. 5-85301. FIG. 6 is a perspective view of an airbelt according to the Publication.
An airbelt apparatus 1 comprises an airbelt 2 diagonally extending from the right of an occupant to the left, a webbing 2a connected to the airbelt 2, a lap belt 3 extending from the right of the occupant to the left, a buckle device 4 disposed on the floor of a vehicle body, etc., a tongue 5 to be inserted into and engaged with the buckle device 4 when the belt is fitted, and a through-anchor 6 for guiding the webbing 2a. 
The webbing 2a comprises a normal belt similar to a conventional and general seat belt, and is slidably guided through the through-anchor 6. One end of the webbing 2a is connected to an emergency-locking seat belt retractor (ELR) 7 so that the retractor can wind the webbing 2a. One end of the airbelt 2 is connected to the other end of the webbing 2a by sewing, etc., and the other end of the airbelt 2 is connected to the tongue 5.
The lap belt 3 is formed of a normal belt similar to a general seat belt, and one end thereof is connected to the tongue 5, while the other end is connected to a seat belt retractor (ELR) 8 fixed to the vehicle body. To the buckle device 4, a gas generator 9 is connected for generating high-pressure gas in an emergency, such as a vehicle collision. The tongue 5 and the buckle device 4 are provided with a path for introducing the gas from the gas generator 9 to the airbelt 2.
In the airbelt 2, a bag having a large width is folded into a small width in a belt shape and is covered by a cover. The airbelt 2 is held in the belt shape in a normal condition. The airbelt apparatus 1 is used in a manner similar to that of a general seat belt. When the gas generator 9 is operated in a vehicle collision, etc., the airbelt 2 is inflated as is shown by the phantom lines so as to protect the occupant.
In the conventional airbelt apparatus described above, the airbelt 2 is connected to the webbing 2a which in turn is wound by the retractor 7. The reason is that when the airbelt 2 is extended so as to be directly guided by the through-anchor 6, wrinkles are formed on the contact surface with the through-anchor 6, and the airbelt 2 is difficult to be smoothly guided through the through-anchor 6, because the difference in the peripheral distance around a guide member is created between an inner-side panel of the airbelt 2 moving directly along the guide member of the through-anchor 6 and an outer-side panel moving along the outer side.
In such an airbelt apparatus, however, in view of an improvement of the occupant-protection ability against a side impulse for a side vehicle collision, etc., there is a case where an inflating section of the airbelt is elongated toward the vicinity of the through-anchor when the airbelt is fitted, so that the airbelt is directly guided by the through-anchor.
It is an object of the present invention to provide an airbelt to be smoothly guided by a through-anchor, etc., when an inflating section of the airbelt is elongated.
It is another object of the invention to provide an airbelt apparatus having the airbelt smoothly guided by the through-anchor.
Further objects and advantages of the invention will be apparent from the following description of the invention.
In the present invention, an airbelt comprises a hollow belt-like cover, and a bag disposed in the cover. The airbelt is inflated by gas introduced into the bag and is guided by a through-anchor member. The cover of the airbelt comprises an inner-peripheral panel on one side of the cover which contacts the through-anchor member and an outer-peripheral panel on the other side. The outer-peripheral panel is elongated in the longitudinal direction of the airbelt when the airbelt is guided by and curved along the through-anchor member.
In a first aspect of the invention, the outer-peripheral panel is elongated in the longitudinal direction of the airbelt when the airbelt is guided by and curved along the through-anchor member.
The outer-peripheral panel may be elongatable in the longitudinal direction by forming the panel from rubber or an elastomer (second aspect). Also, the outer-peripheral panel may be made from a knitted material or a woven material, both materials being elongatable in the longitudinal direction (third aspect).
In an airbelt according to a fourth aspect of the present invention, the inner-peripheral panel may be shortened in the longitudinal direction of the airbelt when the airbelt is guided by and curved along the through-anchor member.
The inner-peripheral panel may be made from a knitted material or a woven material, both materials being elongated in the width direction thereof so as to be shortened in the longitudinal direction when the airbelt is guided by the through-anchor member (fifth aspect).
An airbelt apparatus according to the present invention comprises the airbelt described above, a gas generator for inflating the airbelt, and a through-anchor member for guiding the airbelt. The through-anchor member is a through-anchor or a tongue, for example.
In the airbelt and the airbelt apparatus formed as above, the outer-peripheral panel of the airbelt suspended through the through-anchor member is elongated along the through-anchor member or the inner-peripheral panel is shortened along the through-anchor member, so that wrinkles on an area of the airbelt guided by the through-anchor member are not formed, thereby smoothly moving the airbelt along the through-anchor member.